1. Field of the Invention
The present invention relates to an ink-jet head that performs printing by ejecting ink droplets.
2. Description of Related Art
Some of ink-jet heads that eject ink droplets to recording media include a passage unit and an actuator. The passage unit has individual ink passages each extending from a common ink chamber through a pressure chamber to a nozzle. The actuator applies ejection energy to the pressure chamber, for ejecting an ink droplet from the nozzle. Used as the actuator is, for example, one in which a piezoelectric layer made of a lead zirconate titanate (PZT)-base ceramic material having ferroelectricity is sandwiched between individual electrodes each corresponding to each pressure chamber and a common electrode set at the ground potential. When a splash of ink adheres to such an actuator, a short circuit may undesirably be caused between individual electrodes that are disposed on a surface of the actuator. Thus, as a known technique for preventing a splash of ink from adhering to an actuator, a covering is mounted on a passage unit (see Japanese Patent Unexamined Publication No. 2005-169839, FIG. 3, for example).
In terms of restraining a splash of ink from entering an ink-jet head, it is preferable that an end face of a covering and a passage unit are in perfect contact with each other. However, due to influence of a manufacturing tolerance of the covering or the like, a gap may appear between the end face of the covering and the passage unit. If there is a gap between the end face of the covering and the passage unit, a splash of ink may go through the gap into the ink-jet head and adhere to an actuator. If the gap is large, it is difficult to seal the gap by use of a sealant.